Buck, J.
This case is the result of a conflict between a placer patent and a quartz lode location made subsequent to the application for the placer patent. In investigating the questions involved, we accord full force and effect to the general rule that, where there is a conflict in evidence on a trial, the verdict should not be disturbed on appeal. The verdict in this case, then, must be sustained, if there is competent evidence to support it. We must accept as proven the fact that, at the time the application was made for a patent to the Black placer claim, its surface indicated veins of mineral bearing rock in place. It is true that witnesses on behalf of respondents testified positively that such veins or lodes were in the claim, and plainly visible as veins or lodes at the time of such *346application. But, inasmuch as these witnesses gave in detail the facts on which they based this assertion, these facts, and not the mere assertion based thereon, however positively made, should be considered. The assertion was in the nature of a legal conclusion, being only the expression of an opinion. Hence in what we deem proven by respondents we do not go to any greater extent than to concede that they showed in evidence that the surface appearance of the Black placer, at the date of the application for patent, indicated by croppings and in exposed bedrock the existence of lodes or veins of mineral bearing rock in place.
From the questions submitted to the jury and the argument of their counsel In this court, it would seem that respondents contend for this proposition of law, namely: that when an application for a placer patent is made, any lode or vein of quartz or other rock in place containing any gold, silver, lead, tin or copper whatsoever, known to exist within the boundaries of the claim (or the knowledge of whose existence could be ascertained by one examining the ground in an honest endeavor to acquire such knowledge), is excepted by section 2333, Revised Statutes of the United States, from a patent issued on such application. If this is the law, the determination of this appeal might be attended with more difficulty than it is; for it also appears from the evidence herein — admitted without objection — that some years after the application for a patent for the Black placer claim, in the discovery shaft of the Blue Dick quartz lode claim, sunk on one of the three so-called ‘ ‘traceable veins’ ’ crossing the Black placer at the time of application for its patent, a vein of ore was found carrying as much as 29 ounces of silver to the ton, as shown by one of the two assays made. But we cannot agree with the proposition that this is the law. It virtually eliminates from the question of what is the vein or lode known to exist, the elements of value, character and extent of the existing vein or lode. In Migeon v. Railway Co., 23 C. C. A. 163, 77 Fed. 256, Judge Hawley, speaking for the United States circuit court of appeals, says: “This section (2333) of the statute *347was primarily intended for the benefit and protection of the locators of placer claims. If a lode is known to exist within the boundaries of a placer claim, the applicant for a patent must state that fact, and then, by paying §5 an acre for that portion of the ground and §2.50 for the balance, a patent will issue to him, covering both the lode and placer ground; but, if the lode is known to exist, and is not included in the application for a patent, then it will be construed as a conclusive declaration that the owner of the placer claim has no right of possession by virtue of his patent for the placer ground to the vein or lode. It matters not whether there is a lode or vein actually within the limits, which subsequent developments may prove; if it is not known to exist at the time of the application, the patent for the placer claim will include such lode or vein. In such cases the supreme court has repeatedly declared that it is not enough that there may have been some indications, by outcropping on the surface, of the existence of lodes or veins of rock in place bearing gold or silver or other precious metals, to justify their designation as ‘known veins or lodes;’ that in order to meet that .designation, the lodes or veins must be clearly ascertained, and be of such extent as to render the land more valuable on that account, and justify their exploitation. (Iron Silver Mining Co. v. Reynolds, 124 U. S. 374, 383, 8 Sup. Ct. 598, 603; U. S. v. Iron Silver Mining Co., 128 U. S. 674, 683, 9 Sup. Ct. 195, 199; Iron Silver Mining Co. v. Mike & Starr Gold & Silver Mining Co., 143 U. S. 394, 404, 424, 12 Sup. Ct. 543, 545, 553; Sullivan v. Mining Co., 143 U. S. 431, 12 Sup. Ct. 555; Brownfield v. Bier, 15 Mont. 403, 39 Pac. 461, and other authorities there cited.
“This construction as to the meaning of section 2333 is, in our opinion, founded in reason, and is in harmony with the construction given by the courts to the other sections of the statute relative to the rights of locators of mining claims upon the public lands of the United States. But, in any event, the rule, as above stated, is now too well settled to be departed from. ’ ’ In the case of Iron Silver Mining Co. v. Mike & *348Starr Gold & Silver Mining Co., 143 U. S. 394, 12 Sup. Ct. 543, cited supra; the court says: “It is undoubtedly true that not every crevice in the rocks, nor every outcropping on the surface, which suggests the possibility of mineral, or which may, on subsequent exploration, be found to develop ore of great value, can be adjudged a known vein or lode within the meaning of the statute.” And further the court says : “The amount of the ore, the facility of working and reaching it, as well as the product per ton, are all to be considered in determining whether the vein is one which justified exploitation and working. ” In Brownfield v. Bier, 15 Mont. 403, 39 Pac. 461, the Iron Silver Mining Co. v. Mike & Starr Gold & Silver Mining Co. case, supra, is elaborately discñssed. Our supreme court there says : ‘ £But in that case the contention within the court seems to us to have been more upon the question of facts in that particular case than upon a view of the law;” and proceeds to quote, as declaratory of the law, language taken from the majority opinion of the court, and also from the dissenting opinion rendered therein by Mr. Justice Field and Associate Justices Harlan and Brown. Certain portions of this language are requoted below.
But the respondents urge, to meet this view entertained by the -Montana supreme court of what was held in the Mike & Starr Gold & Silver Mining Go. case, that the question of value is one solely for the jury, and the facts in this case are stronger in favor of the verdict than those successfully invoked for the same purpose in the Mike & Starr Gold & Silver Mining Co. case. This language is relied upon from the last-named decision to uphold the first contention : £ ‘It is, after all, a question of fact for the jury. It cannot be said, as a matter of law, in advance, how much of gold or silver must be found in a vein before it will justify exploitation, and be properly called a £known’ vein. ’ ’
As to what were the particular facts involved in the Mike & Starr Gold & Silver Mining Co. case, the justices of the supreme court of the United States were divided in opinion, and this fact led the supreme court of Montana to use the language *349it did in Brownfield v. Bier, supra. The majority of the justices claimed the record showed that, prior to the application for a patent to the placer claim of the Iron Silver Company, within the limits of said placer a tunnel had been run to the extent of 400 feet; that in said tunnel, about 75 or 80 feet from its mouth, a 15-inch vein of quartz, with distinct walls of porphyry, had been disclosed; and • that assays of the ore taken from this vein had been made (apparently at the time it was found), showing that the same was valuable gold producing ore. Speaking of the facts involved, Mr. Justice Brewer, in delivering the opinion for the majority of the court, said: “The placer tract was a small one of fifty-six acres. The tunnel ran 400 feet underneath its surface. At its mouth there was a large dump of earth taken from it. No one had a right to enter that ground as placer-mining ground, unless he had made such an inspection as to enable him to make affidavit that it was adapted to such mining. No examination could have been made without disclosing the existence of this tunnel. That was a fact upon the surface, obvious to the most casual inspection. No one could be heard to say that he had examined that ground in order to ascertain that it was suitable for placer mining, and in such examination had not discovered the existence of this tunnel. It was not a little excavation, with a few shovelfuls of dirt at its entrance. The pile of dirt was evidence which no one could ignore that it was a long tunnel, running far into the earth. It was in mining ground, as all this territory was believed to be, and, therefore, an excavation likely to disclose veins.
‘ ‘As an applicant for a placer patent was chargeable with notice of the existence of the tunnel, so also was he chargeable with notice of whatever a casual inspection of that tunnel would disclose. He would not be heard to say: ‘I did not enter and examine this tunnel, and therefore knew nothing of the veins apparent in it. ’ The government does not permit a person to thus shut his eyes and buy. If there be a vein or lode within the ground, it is entitled to double price per acre for it and the adjacent fifty feet; and, with such interest in the price *350to be paid, it rightfully holds an applicant for a placer patent chargeable with all that would be disclosed by a casual inspection of the surface of the ground, or of such a tunnel. The applicant must be adjudged to have known that which others knew, and which he would have ascertained if he had discharged fairly his duty to the government.” But Mr. Justice Field, in the dissenting opinion, says: “It (the tunnel) extended 400 feet, but it disclosed within it only veins of decomposed porphyry and manganese iron. * * * There was no vein or lode of gold or silver bearing rock found in the tunnel, and there is an erroneous impression conveyed by the court (in the majority opinion) in that respect.” Proceeding, Justice Field says: “But, as I shall show hereafter, the mere indication or presence of gold or silver is not sufficient to establish the existence of a lode. The mineral must exist in such quantities as-to justify expenditure of money for the development of the mine and the extraction of the mineral. It would create surprise among miners to be told that if a trace ■ of loose gold, such as is shown here, was found at any one spot in a tunnel leading to a placer claim, it would establish the existence of a vein or lode in the placer claim, and form the basis of a proceeding to despoil a purchaser from the patentee, years after the purchase, of a large portion of its mining property. * * * An unlocated lode claim, existing only in the impressions and beliefs of neighbors or others, and not in the knowledge founded upon discovery and exploration, does not seem to me to have any element of property or validity, or a basis of defense to proceedings to obtain a patent from the government. ” As we have said, there were indications of veins in the Black placer at the time of the application for its patent. It is true that what appeared to be veins had been exposed between walls of granite in the bedrock. But not a particle of competent or sufficient evidence was offered by respondents (on whom rested the burden of pro of) to establish the fact that these veins had been clearly ascertained, or contained minerals sufficient as to value, quantity, or character to justify exploitation. Even by respondents’ *351own witnesses these quartz-filled crevices in the granite bedrock of the Black placer (that witnesses designated them positively as veins or lodes, as we have shown, was not sufficient evidence of the fact that they were) had never been explored, or even examined, with a view to prospecting or working them during the placer mining period. They were encountered just as strata seams and quartz filled crevices were usually encountered at the surface and on bedrock in working other placer mines in that vicinity. No serious attempt had been made to prospect or exploit them. A witness who sunk on some of them says ‘ ‘they played out. ’ ’ Another witness dissuaded his partner from locating one of them, which he designates as the ‘ ‘main vein, ’ ’ by suggesting that they had already a hundred locations too many. His partner, this witness says, regarded this vein at the time as a ‘ ‘favorable prospect, ’ ’ Hirbour, the locator of the Leo quartz lode, may possibly have sunk a shaft for a few feet on one of these so-called “traceable veins,” but he found practically nothing. He says he took out a few pounds of ore. Largey struck what he calls a “blind lead” in his quartz lode claim, the Montana Central, which was located after the application for the placer patent. He says that at the point where he made his discovery of a blind lead the croppings (which extended from said point into the Black placer ground) were detached from the vein he found, and were only float. He states also that he sunk shafts within the Black placer on these so-called veins or leads, but did not even find as a result any vein with well defined walls. Largey may have been an interested witnsss, but the respondents put him upon the stand as their own witness, and we cannot find any testimony in the record which substantially contradicts his statements. The fact, of itself, that Largey and the owners of the Black placer were to exchange interests in their grounds by way of compromise, is not competent evidence to establish the value of the Montana Central quartz lode vein for exploitation at the date of the application for the placer patent. At the time of the application for patent, so far as the testimony for respondents shows, the extent and *352definite character of the quartz in these crevices in the Black placer were unknown. No assays "had been made of the quartz found on bedrock or elsewhere. The ground itself had been worked as a placer mine for years, and, according to all the witnesses who testified on the subject of the value of the quartz therein, was considered valuable for placer mining only. That quartz ore of value was found in the Blue Dick discovery ' shaft cannot avail respondents. The location of the Blue Dick was made some eight years after the application for the Black placer patent. However, no great amount of work (so far as the record discloses) had ever been performed in exploiting the Blue Dick vein. There was little evidence to show the value or extent of this vein. At the time of the trial of this suit in the lower court its discovery shaft was half full of water. Two of its locators had dwellings and outhouses on the ground before they made the location, and they were conducting a wood business on the premises at the time of the location. One of them had entered into possession of the premises in dispute under a deed from one Upton, who apparently had some kind of a possessory right to the ground. In 1888 one of the respondent defendants received two deeds from these locators, one of which conveyed to him a certain part of the property in dispute ("described with reference to the surface area), on which there was a dwelling house, and the other an interest in the Blue" Dick. This evidence was insufficient to present a question of fact for the jury under the law applicable.
We reiterate the rule as laid down, after a careful review of the authorities, in Brownfield v. Bier, 15 Mont. 403, 39 Pac. 461, that to meet the designation “known” veins or lodes mentioned in section 2333, Revised Statutes of the United States, veins or lodes within the boundaries of a placer claim at the time of the application for a patent therefor, which should be excepted from a patent issued thereon, must, at the time of the said application, have been clearly ascertained, and must have been of such an extent, character, and value as to justify their exploitation. Conceding everything as proven which can in any possible view of the evidence be regarded as *353advantageous to respondents, we are still of opinion that they clearly failed to make out their case. It follows that the special findings of the jury did not justify the general verdict and judgment. There was hardly any temptation to Black, when he applied for a patent, to perpetrate a fraud on the government. By paying $10 more for the four-acre placer, he could have had any quartz leads thereon specifically conveyed to him. Mr. Justice Field, stating the law as to presumptions in favor of government patents, says, in his dissenting opinion in the Mike & Starr Gold & Silver Mining Company case, supra: “ The presumption in favor of its validity attends the placer patent, as it does all patents of the government of any interest in the public lands which they purport to convey. So potential and efficacious is such presumption that it has been frequently held by this court that if, under any circumstances in the case, the patent might have been rightfully issued, it will be presumed, as against any collateral attack, that such circumstances existed. (Smelting Company v. Kemp, 104 U. S. 636, 646.) As was said by the circuit court in the Eureka Consolidated Mining Company case, 4 Sawy. 302, Fed. Cas. No. 4,548, a patent for a mining claim is ironclad in its potency against all mere speculative inferences. ” The tendency of the later decisions of the federal courts is to uphold the presumptions in favor of placer and townsite patents more carefu.ly than appears to have been done in some of the earlier decisions of those courts in conflicts between such patents and subsequently located quartz lodes. This is particularly noticeable in the late case of Dower v. Richards, 151 U. S. 658, 14 Sup. Ct. 452. Perhaps one reason for this is the fact that it has not infrequently happened, in cases involving such conflicts, where the ground in dispute lies within an inhabited portion of a town or city, that the courts have been appealed to and compelled to determine them under the rules of law governing mineral locations, while underlying the apparent issue the real source of controversy was the desire to acquire title to land only nominally valuable for mining purposes. Whether this is true or not, however, in all such cases *354where persons locate a quartz lode within a placer claim which lies in a town or city, or in a townsite, subsequent to the application for a patent to the one or the other, the evidence as to the existing known lead justifying a decision in favor of the quartz lode claimants should be clear and convincing, and not made up of surmise or mere personal impressions and beliefs. Were this not true, honestly acquired town-lot titles in populous mining towns and cities, based on such patents, would be constantly in jeopardy, and subject to possible attack at any time when, in the digging of a cellar or the foundation for a house, a vein of quartz should be disclosed. The upsetting of vested rights to such realty, years after the patents under which they have been acquired were applied for, should never be encouraged or tolerated when based on frivolous or insufficient grounds. In the enactment of the mineral laws, congress never contemplated any such result.
Respondents pleaded the statute of limitations as against plaintiffs, but, inasmuch as they have themselves abandoned this phase of the case, we need not discuss it. Numerous other errors are assigned, particularly in reference to the instructions given by the lower court. But these also it is unnecessary to pass upon. The judgment is reversed, and the cause remanded, with directions to the district court to grant a new trial.
Reversed and remwnded.
Hunt, J., concurs. Pemberton, C. J., not sitting.