Bert Davids, an enrolled member of the Stockbridge-Munsee Indians, appeals a judgment of conviction for violation of § 29.09(1), STATS., fishing without a license. Davids argues that the State lacks jurisdiction to convict him of fishing without a license under § 29.09(1).1 Specifically, Davids claims that the 1856 Treaty between the Stock-bridge-Munsee and the United States created a reservation and gave tribal members the right to hunt and fish within the boundaries created by the Treaty. He asserts that Congress never diminished or disestablished the reservation boundaries, or terminated the Tribe's hunting and fishing rights within those boundaries. Because he was exercising his treaty-given rights to fish within those boundaries, Davids concludes that he was fishing within Indian country and *192that the State lacks jurisdiction over him. We agree with Davids and reverse the conviction.
On May 5, 1991, Davids was cited by a Wisconsin Department of Natural Resources warden for fishing at Upper Gresham pond without a fishing license in violation of § 29.09(1), Stats. The pond is located within the boundaries of the Stockbridge-Munsee Indian reservation as created by the 1856 Treaty. Davids challenged the citation and moved to dismiss, arguing that the State lacked subject matter jurisdiction because he was exercising a treaty-based right to fish within Indian country.
The trial court concluded that it had jurisdiction, denied his motion and convicted him of violating § 29.09(1), Stats. The court's jurisdictional analysis was based on its review of the legislative history and effect of a series of congressional acts. The court agreed that the 1856 Treaty between the Stockbridge-Munsee and the United States established a reservation on the present day towns of Bartelme and Red Springs. This reservation encompassed Upper Gresham pond. The court also apparently assumed that the Treaty gave the Tribe hunting and fishing rights within those boundaries.
However, the court concluded that an 1871 Act of Congress diminished the reservation boundaries and that the pond was outside the diminished reservation. It further concluded that a 1906 Act terminated the remaining reservation, and that this termination simultaneously terminated the Tribe's hunting and fishing rights. The court concluded that a new, and smaller, reservation was created in the 1930s within the boundaries of the original reservation. The court held that the new reservation gave the Tribe hunting and fishing rights within those boundaries, but, *193because Upper Gresham pond is not located within the new reservation, the court held that the State had exclusive jurisdiction over hunting and fishing on those lands.
On appeal, Davids argues that the Acts the trial court relied upon did not diminish or disestablish the reservation boundaries, nor did they extinguish treaty-given rights to hunt and fish within those boundaries. The State's arguments mirror the trial court's reasoning and conclusions.
The State's jurisdiction to regulate Stockbridge-Munsee fishing on Upper Gresham pond hinges upon whether the pond is in Indian country within the meaning of 18 U.S.C.A. § 1151 (1984). That section includes in the definition of Indian country "all land within the limits of any Indian reservation under the jurisdiction of the United States Government, notwithstanding the issuance of any patent . . . ." The State concedes that if the pond is within the Tribe's reservation boundaries, and thus within Indian country, it has no jurisdiction.2
*194It is undisputed that the Treaty of 1856 created a reservation encompassing the towns of Bartelme and Red Springs, and that this reservation included Upper Gresham pond. It is further undisputed that the Treaty gave the Tribe the right to hunt and fish within those boundaries. However, the pond's status depends upon whether the original reservation boundaries remain unchanged or whether they were diminished, disestablished and reestablished by congressional acts. Whether reservation boundaries have been diminished or disestablished by congressional act is a question of law. We review questions of law de novo. Brown County Attorneys Ass'n v. Brown County, 169 Wis. 2d 737, 741, 487 N.W.2d 312, 313 (Ct. App. 1992).
We begin by reviewing some well-established legal principles. The first of these is that only Congress can divest a reservation of its land and diminish its boundaries. Once a reservation is created, no matter what happens to the title of individual plots within the area, the entire block retains its reservation status until Congress explicitly indicates otherwise. Solem v. Bartlett, 465 U.S. 463, 470 (1984); see also State v. Webster, 114 Wis. 2d 418, 430, 338 N.W.2d 474, 480 (1983).
Additionally, diminishment is not lightly found, but requires an Act that clearly evinces congressional intent to change boundaries. Solem, 465 U.S. at 470. This is important because toward the end of the nineteenth century, the assumption in Congress was that *195Indian tribes would shortly enter traditional American society and the reservation system would cease to exist. Consequently, Congress was not always meticulous in specifying whether particular legislation formally sliced off a parcel of a reservation. Id. at 468. Yet the courts have never extrapolated an intent to diminish reservation boundaries in a specific act from this general congressional understanding and carelessness. Rather, courts must always examine each act for clear evidence of congressional intent to diminish before diminishment is found. Id. at 468-69.3
*196There are three primary factors to consider in determining congressional intent to diminish reservation boundaries: "the face of the relevant act, events surrounding its passage, including legislative history, and subsequent treatment of the land." United States v. Grey Bear, 828 F.2d 1286, 1289 (8th Cir. 1987). The most probative evidence of intent is the statutory language used in the act. "Explicit reference to cession or other language evidencing the present and total surrender of all tribal interests strongly suggests that Congress meant to divest from the reservation" certain lands. Solem, 465 U.S. at 470. When such language is buttressed by an unconditional commitment from Congress to compensate a tribe for its land, there is almost an insurmountable presumption of congressional intent to diminish. Id. at 470-71.
Clear examples of explicit language evincing an intent to diminish reservation boundaries exist. In DeCoteau v. District County Court for Tenth Jud. Dist., 420 U.S. 425, 437 (1975), the Court found a Sioux agreement to "cede, sell, relinquish, and convey to the United States all the unallotted land within the reservation" evinced an intent to diminish the boundaries. In Mattz v. Arnett, 412 U.S. 481, 504 n.22 (1973), Justice Blackmun cited three examples of such language: 15 Stat. 221 (1868) ("the Smith River reservation is hereby discontinued"); 27 Stat. 63 (1892) (a portion of the Colville Indian Reservation is "vacated and restored to the public domain"); 33 Stat. 218 (1904) ("the reservation lines of the said Ponca and Otoe and Missouria Indian reservations be, and the same are hereby abolished").
*197However, explicit language of cession is not a prerequisite for finding diminishment. Solem, 465 U.S. at 471. An intent to diminish may be inferred when events surrounding passage of an act unequivocally reveal a widely held contemporaneous understanding that the affected reservation would shrink. Id. Additionally, treatment of an affected area by Congress and the Bureau of Indian Affairs, particularly in the years immediately following the opening of an area, has some evidentiary value in discerning congressional intent. Id. However, when an act and its legislative history fail to provide substantial and compelling evidence of a congressional intent to diminish, the traditional solicitude due Indian tribes compels us to rule that diminishment did not take place and that a reservation's boundaries survived an opening. Id. at 472; see also Webster, 114 Wis. 2d at 430, 338 N.W.2d at 480.
THE ACT OF 1871
We first apply these principles to the Act of Feb. 6, 1871, ch. 38, 16 STAT. 404. That Act was designed to resolve a dispute between two factions of the Stock-bridge-Munsee Tribe. The factions, known as the Citizen party and the Indian party, had a long history of disputes. Members of the Citizen party were Stock-bridge-Munsee Indians who wished to separate themselves from the Tribe and become citizens of the United States. The Indian party members wished to retain their tribal character and continue under the care and guardianship of the United States. Id. at § 6.
The Act attempted to resolve the dispute in the. following manner: Under the supervision of the Secretary of the Interior, reservation land within the 1856 boundaries was appraised and auctioned off in eighty-*198acre lots, with the exception of eighteen sections of land. Id. at §§ 1, 2. Money raised from the sale was divided between the Citizen and Indian parties in proportion to the number of Indians in each party. The Citizen party's portion of money from the sale was equally divided among them per capita, and paid to the head of families and adult members. Id. at § 5. The payment was held
as a full surrender and relinquishment on the part of the citizen party, each and every one of them, of all claims to be thereafter known or considered as members of said tribe, or in any manner interested in any provision heretofore or hereafter to be made by any treaty or law of the United States for the benefit of said tribes, and they and their descendants shall thenceforth be admitted to all the rights and privileges of citizens of the United States.
Id. at § 6 (emphasis added).
The portion due to the Indian party was held in trust for them by the United States. Id. at § 5. The Act went on to hold that these Indians "may be located upon lands reserved by the second section of this act, or such other reservation as may be procured for them . . . ." Id. at § 7 (emphasis added). The second section of the Act authorized the Secretary of the Interior to "reserve from sale" eighteen sections of land. The Act also provided that "as soon as practicable, after a suitable and permanent reservation shall be obtained and accepted by said tribe, either at their present home or elsewhere, the same shall... be surveyed and subdivided ...." Id. at § 8 (emphasis added). Following subdivision, allotments from the land were to be made to tribal members.
*199Our review of the 1871 Act does not disclose any clear language of cession of reservation boundaries resembling the examples cited earlier. Furthermore, we can find no unconditional congressional commitment to compensate the Tribe for its lands. Solem suggests this requires guarantee of a certain amount of compensation. Id. at 469 n.10. Where, however, the compensation is uncertain and the Secretary of the Interior is authorized to conduct the sale of the land and credit the Tribe with the proceeds, the Secretary is merely acting as a sales agent for the Tribe and there is no evidence of an unconditional commitment to compensate the Tribe for diminished lands. Id. at 469 n.10, 473 (citing Seymour v. Superintendent, 368 U.S. 351, 356 (1962)). Because the amount of compensation guaranteed by the auction was uncertain, and because the Secretary was authorized to conduct the sale and credit accounts, we conclude that the Secretary was merely acting as the Tribe's sales agent.4
*200The State argues that the language from the Act placing the Indian party on the eighteen sections reserved from sale, when placed in historical context, evinces a clear intent to create a new reservation for the Indian party. Specifically, in the 1840s and 1850s, the Tribe was located on a reservation encompassing two townships on the edge of Lake Winnebago. However, continual infighting among tribal factions led Congress to enter into a Treaty in 1848 whereby the Tribe would remove to a new reservation in Minnesota. A majority of the Tribe, however, refused to remove and wished to move to a new reservation in Wisconsin. Still others preferred to disassociate themselves from the Tribe altogether. Treaty with the Stockbridge and Munsee, 1856, pmbl., 11 STAT. 663.
Finally, in 1856, Congress and the Tribe entered into a new treaty whereby those members of the Tribe wishing to remove to a new location were given the reservation at Bartelme and Red Springs. Those who wished to disassociate themselves from the Tribe were given patents to land at the town of Stockbridge in exchange for ceding and relinquishing to the United States all their rights as members of the Tribe. Id. at ART. 16.
The State argues that seen through this historical context, the 1871 Act clearly was intended to do what the 1856 Treaty did: make citizens of those who no longer wished to be part of the Tribe and locate the remaining Tribe on a new reservation, either in Minnesota or a diminished reservation at their present location. We believe this is a plausible interpretation of congressional intent behind the 1871 Act. We cannot say, however, that Congress clearly intended this. It is *201equally plausible that Congress sought to resolve the dispute by giving Indian party members the choice of either removing to a new reservation or remaining within the unchanged 1856 boundaries on the remaining eighteen sections of land held in trust for them.
Prior to 1871, Congress had a history of disestablishing Stockbridge-Munsee reservations in unequivocal terms. The 1839 Treaty begins: "The Stockbridge and Munsee tribes of Indians (formerly of New York) hereby cede and relinquish to the United States, the east half of the tract of forty-six thousand and eighty acres of land, which was laid off for their use ...." Treaty with the Stockbridge and Munsee, 1839, 7 Stat. 580, 11 Stat. 577 (emphasis added). Similarly, the 1856 Treaty disestablishing the reservation on Lake Winnebago stated that "[t]he Stockbridge and Munsee tribes . . . and all the individual members of said tribes, hereby jointly and severally cede and relinquish to the United States all their remaining right and title in the lands at the town of Stockbridge_" Treaty with the Stockbridge and Munsee, supra, ART. 1 (emphasis added). It is evident that Congress, in its prior dealings with the Stockbridge-Munsee, was in the habit of using clear language of cession to disestablish previous reservations.5 Even the 1871 Act used clear *202and unambiguous cession language to terminate the Citizen party's membership in the Tribe and its members' tribal rights vis-a-vis the United States. In the absence of similarly clear language ceding the Tribe's reservation boundaries, and in the face of that Act's ambiguous meaning, we decline to hold that Congress clearly evinced its intent to diminish the 1856 reservation. See, e.g., Mattz, 412 U.S. at 504.
THE ACT OF 1906
The Act of June 21, 1906, ch. 3504, 34 STAT. 382, declared that "members of the Stockbridge and Munsee tribe of Indians . . . shall, under the direction of the Secretary of the Interior, be given allotments of land and patents therefor in fee simple . . . ." The Act made allotments from all the available land in the reservation until available reservation land was exhausted. This available land came from unalloted land within the eighteen sections of land reserved from sale by the 1871 Act. As with the 1871 Act, the 1906 Act does not use cession language similar to the clear cession language used in the previously cited treaties; the statutory language does not clearly evince an intent to diminish or disestablish the reservation.
The State argues that this Act, when read in context with the 1871 Act diminishing the reservation boundaries, was intended to disestablish the remaining diminished reservation. Having held that the 1871 Act does not clearly evince an intent to diminish the reservation boundaries, the State's argument loses some of its force. The State also relies on the fact that this Act was the result of an agreement between the Stockbridge-Munsee and the United States. Apparently, a majority of the Tribe's males had petitioned the government with a proposed plan to settle the Tribe's *203affairs. Pursuant to the plan, they petitioned for a patenting of all remaining tribal land and agreed to
accept the following conditions as a full and complete settlement of all obligations of the Government, of whatever nature or kind, either expressed or implied, from whatever source the same may have accrued . . . and upon performance by the Government of said conditions any and all claims, grievances, and rights which we may have or claim to have against the Government... shall be deemed to have been fully paid, satisfied, and discharged.6
Even assuming this agreement would have dissolved the Tribe and disestablished the reservation, Congress never ratified the agreement. Legislation was twice introduced to Congress for the purpose of "carrying into full force and effect the intent and meaning of said agreement," and both times the legislation failed.7 The 1906 Act makes no mention of the Tribe's offer, but rather merely issued fee patents to members for the remaining unallotted land on the reservation. However, the issuance of allotments and patents cannot by itself serve to disestablish reservation boundaries. Under 18 U.S.C. § 1151 (1984), Indian country includes reservations "notwithstanding the issuance of any patent . . . ." Mattz, 412 U.S. at 504. Thus, we conclude that nothing in the language or the legislative history of the 1906 Act evinces a clear congressional intent to disestablish the remaining *204boundaries as they existed when created by the Treaty of 1856.
Our conclusion that the reservation was never disestablished, or the Tribe dissolved, is buttressed by subsequent treatment by the Bureau of Indian Affairs. In a 1974 letter to the chairman of the Tribe, the acting commissioner of Indian Affairs from the Department of the Interior's Bureau of Indian Affairs expressed his opinion that Congress never clearly evinced an intent to diminish or disestablish the reservation, and that the 1856 boundaries remained intact. A similar opinion was expressed by the acting director of the Bureau of Indian Affairs' Office of Trust Responsibilities in a 1980 letter to the town clerk of Red Springs.
Additionally, current maps issued by the Department of Interior show the Stockbridge-Munsee reservation boundaries as they were established in 1856. One of these maps is a United States Geological Survey Map of Gresham Quadrangle, 7.5 minute series. The other is a Bureau of Indian Affairs Great Lakes Agency map of the present reservation. While we disagree with Davids' assertion that the letters and maps are themselves dispositive of the issue of the present reservation boundaries, they constitute some evidence that Congress never evinced a clear intent to, and thus, did not, diminish the 1856 boundaries.
Because the reservation boundaries were never diminished, Davids was fishing within Indian country. Because the State has conceded the Tribe has the right to hunt and fish free of State interference in Indian country, we conclude that the State had no jurisdiction to cite Davids for violation of § 29.09(1), Stats. Accordingly, the conviction is reversed.
*205By the Court. — Judgment reversed.
Section 29.09(1), STATS., states:
Except as specifically provided otherwise by s. 29.155(1) or another section of this chapter, no person may hunt any wild animal, trap any game or fish for fish in the waters of this state unless the appropriate approval is issued to the person. A person shall carry the required approval with him or her at all times while hunting, trapping or fishing unless otherwise required by another section of this chapter or unless otherwise authorized or required by the department. A person shall exhibit the approval to the department or its wardens on demand.
The State lacks jurisdiction over fishing, as well as hunting and trapping, on reservation land for several reasons. First, § 29.025, Stats., states "American Indians hunting, trapping, or fishing off Indian reservation lands are subject to this chapter." Thus, by implication, ch. 29 is inapplicable to Indians who hunt, fish and trap on reservation lands. Second, and relatedly, 18 U.S.C.A. § 1162(a) (1984) giving Wisconsin jurisdiction "over offenses committed by or against Indians in the areas of Indian country" within the State specifically prevents the State from depriving "any Indian or any Indian tribe, band, or community of any right, privilege, or immunity afforded under Federal treaty, agreement, or statute with respect to hunting, trapping, or fishing or the control, licensing, or regulation thereof." Id. at subsec. (b). Finally, the State's jurisdiction is arguably preempted because the tribe has enacted its own fish and game *194laws which, if construed as an exercise of its sovereign power over its reservation, precludes the exercise of state fish and game laws within the reservation. See, e.g., St. Germaine v. Chapman, 178 Wis. 2d 869, 505 N.W.2d 450 (Ct. App. 1993).
The dissent's reliance on Montana v. United States, 450 U.S. 544 (1981), is misplaced for two reasons. First, the dissent's quotation is a reference to Congress' understanding of the effect of the General Allotment Act of 1887, 24 Stat. 388. Neither party argues this Act is relevant to the issue before this court, nor could they because congressional intent in 1887 cannot be imputed to the 1871 Act passed sixteen years earlier. If the General Allotment Act is relevant at all, it is as another example of Congress' general understanding about the future of the reservation system. Yet as we have just noted, Solem v. Bartlett, 465 U.S. 463, 468-69 (1984), places no significance on the general understanding but requires a specific indication of its intent to diminish a reservations boundaries.
Second, Montana involved the question of whether the Tribe retained the jurisdiction to enforce its hunting and fishing laws against non-Indians living on allotted land that was within its reservation. The case does not suggest that allotments diminished the reservation boundaries, but rather that the Tribe lost jurisdiction to enforce its laws on non-Indians on those lands. Presumably, because these lands remained within the reservation boundaries, the Tribe retained the right to hunt and fish on allotted lands, subject to the owner's permission, free from State jurisdiction.
Justice Marshall noted in Solem v. Bartlett, 465 U.S. 463 (1984), that Seymour v. Superintendent, 368 U.S. 351 (1962), was a good illustration of when a surplus land act did not diminish reservation boundaries.
At the other extreme, the Act of Mar. 22, 1906, ch. 1126, § 1, 34 Stat. 80, simply authorized the Secretary of the Interior to "sell or dispose of' unallotted lands on a portion of the Colville Indian Reservation; under the Act, the Colville Tribe received whatever proceeds these sales generated, rather than a sum certain. § 9, 34 Stat. 81. In Seymour ... we held that, because the Colville Act lacked an unconditional divestiture of Indian interest in the lands, the Act simply opened a portion of the Colville Reservation to non-Indian settlers and did not diminish the reservation.
Solem, 465 U.S. at 468 n.10. While the 1871 Act was not a land surplus act, we believe its compensation structure resembles *200the Colville Act of Seymour, which Justice Marshall said was an example of an Act that did not diminish reservation boundaries.
Even the Treaty with the Menominee, 1856, 11 Stat. 679, used clear language of cession. This treaty disestablished a portion of the Menominee reservation so that Congress could create the Stockbridge-Munsee reservation at the towns of Bartelme and Red Springs. Article 1 of the treaty states: "The Menomonee tribe of Indians cede to the United States a tract of land, not to exceed two townships in extent... for the purpose of locating thereon the Stockbridge and Munsee Indians . . . ." (Emphasis added.)
S. REP. No. 173, 58th Cong., 2d Sess., 21 (1904).
The first bill (S. 3620) was introduced in the 57th Congress in 1902. The second bill (S. 335) was introduced in the 58th Congress in 1903. S. Rep. No. 173, supra note 6, at 2,17.